A Dynamic Web Template is an HTML-based master copy of a web page that you can create to contain settings, formatting, and page elements such as text, graphics, page layout, styles, and regions of a web page that can be modified.
You attach a Dynamic Web Template to the pages in a website, and that template defines the layout for those pages.
You can use any number of Dynamic Web Templates in a website, and you can attach a Dynamic Web Template to as many pages as you like.
By using Dynamic Web Templates, you can create HTML pages that share the same layout. In addition to providing a shared layout, you can make some regions in a template available for editing while preventing changes to other regions in that template.
This means that you can allow others to add and edit content, yet still preserve the layout of the pages and the template itself.